Zeltiq Aesthetics IPO prices below estimates

The initial public offering of Zeltiq Aesthetics Inc. priced below expectations, but shares are rising in midday trading.

Zeltiq developed the CoolSculpting System, which is designed to selectively reduce stubborn bulges of fat that may not respond to diet or exercise. The company says its IPO of 7 million shares priced at $13, below its estimate of $14 to $16.

However, the stock rose $2.63, or about 20 percent, to $15.63 in midday trading while the broader markets were mixed.

Shares of the Pleasanton, Calif., company are trading on the Nasdaq Global Select Market under the symbol "ZLTQ."

Zeltiq's IPO is only the second completed initial public offering in the last two months. Technology company Ubiquiti Networks Inc. completed its IPO on Thursday. The company cut its expected price range before shares started trading, and the stock priced at the low end of its revised estimate. Before that, the IPO market had been quiet amid growing uncertainty in the global market.

Zeltiq said the underwriters of its IPO have an option to buy another 1.1 million shares to cover any over allotments.